Collagenase activity of rat kidney with glomerulonephritis is inhibited by erythromycin.

Collagenolytic activity of rat kidney with glomerulonephritis (GN) of Masugi's type was determined by a series of biological experiments. The determination was carried out during the heterologous phase of the disease together with inhibition studies in vivo and in vitro. Erythromycin has been tested in vivo for its inhibitory activity and an activity of collagenase was found in untreated rats with GN only, the panel treated with erythromycin did not show any collagenolysis. Statistical calculations indicate the significance of the inhibition (p less than 0.001). In addition, kidneys of test animals with GN have been investigated for their enzymatic activity and the inhibition by erythromycin in vitro where the kidneys failed to show collagenolytic activity. It can be concluded that erythromycin is able to inhibit in vivo and in vitro the activity of the collagenolytic enzyme produced by polymorphonuclear leukocytes during the heterologous phase of the nephritis, an effect which leads to the recovery of the physiological equilibrium of the protease and its inhibitor.